In the past, various types of amchines for cases, e.g., cardboard boxes, have been developed. Generally herein referred to as case handling machines, such machines include machines for assembling or erecting cases, machines for sealing cases and machines for placing inserts in cases, plus various combinations thereof. For example, some case handling machines both erect cases and, then, partially seal the erected cases. Other case handling machines merely seal cases. In some instances, sealing is accomplished using an adhesively coated tape. In other instances, an adhesive is applied directly to the major and/or minor flaps of the case to be sealed.
In the past, programmable controllers have been developed for controlling the operation of the case handling machines. See for example, U.S. Pat. Nos. 4,515,579; 4,516,210 and 4,545,175, all assigned to the assignee of the present application. While case handling machines including programmable controllers of the type described in these patents have a substantial advantage over semi-automatically controlled case handling machines, in the past, case handling machines controlled by such programmable controllers have had a significant disadvantage when utilized in environments requiring readjustment of the case handling machine from time to time in order to handle different sized cases.
More specifically, depending upon the machine, selected elements of case handling machines are designed to be movable so that one machine can handle various sized boxes. The movable elements may include, for example, the horizontally oriented rails and/or a head that supports various elements, such as flap positioning devices, glue heads, etc. In many machines, rails are moved inwardly and outwardly to adjust the machine to handle boxes of different widths and the head is raised and lowered to adjust the machine to handle boxes of different heights.
In the past, the movable elements of case handling machines have all been manually adjusted. That is, in order for the configuration of a case handling machine to be changed to handle a different size box, prior art machines have required the operator to manually readjust the movable elements of the machine. Readjustment usually entailed the rotation of handwheels connected to ball-screw mechanisms, the closure of switches connected to electric motors, etc. Obviously, the manual readjustment of a case handling machine is a time-consuming and, thus, undesirably expensive task, particularly when a case handling machine is part of a high-speed packaging line.
The present invention is directed to avoiding the foregoing disadvantage by providing a programmable controller for case handling machines that controls the position of the movable elements of the machine based on the size of the particular box or case to be handled. While the invention is described in connection with one type of case handling machine, it is to be understood that the programmable controller of the invention can be utilized with other types of case handling machines.